The first result which proved () for \(H=-\Delta +V\)  in dimensions \(d\ge 3\)  was obtained by Journé, Soffer, and Sogge [1]}. Following unpublished work by Ginibre, we now give a short proof of a simpler estimate, namely
\(\Vert e^{itH} P_c f\Vert _{L^\infty +L^2({\mathbb {R}}^d)} \lesssim \langle t\rangle ^{-\frac{d}{2}} \Vert f\Vert _{L^1\cap L^2({\mathbb {R}}^d)}\) 
